Safety-fuse.



H. A. YATES.

SAFETY FUSE.

Patented vJune 4, 1912.

APPLICATION FILED JULY 11,1911.

5141 vanto/z Mies flrtoznu) UNITED STATES PATENT OFFICE.

HARRY A. YATES, OF NEW YORK,

N. Y., ASSIGNR, BY MESNE ASSIGNMENTS, TO THE Y. & G. ELECTRIC FUSE & ENGINEERING COMPANY, A CORPORATION OF NEW JERSEY.

SAFETY-FUSE.

Application led July 11, 1911. Serial No. 637,881.

To all whom it may concern Be it known that I, HARRY A. Yarns, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Safety-Fuses, of which the following` is a specification.

The present invention relates to certain 4novel and useful improvements in thermal cut-outs for electric circuits, and has particular application to a type of safety fuse, wherein the fusible conductor is melted under a heavy overload, or when a short circuit occurs, thereby forming an open circuit.

In carryingl out my invention, it is my purpose to provide a safety fuse for electric circuits which will embrace the desired features of simplicity, eiliciency, and econonly in cost of manufacture and installation.

Furthermore, I aim to provide a safety fuse wherein, when operated through an overload or short circuit, the fusible element will be ruptured, and broken up into sections, which will fall or drop back into the shell or cylinder of the fuse body, thereby breaking the circuit and at the same time preventingl the formation of an arc.

Still another object ofthe invention is to provide a form of safetyfuse, in which the parts are so constructed and arranged that when the fusible conductor has been melted and broken up into sections, the circuit can .not be restablished by a person inserting a piece of conducting' wire in the shell or c vlinder, and connecting the terminals at the faps. It is frequently the practice for an operator to reestablish the circuit, after the safety fuse has been ruptured, in the manner above mentioned, with 4the result that the electrical equipment is oftentimes seriously damaged by short circuits and extremelv heavy overloads. TVith the use of myV fention, however, the possibility of the workman so restablisl'iing the circuit obviatd. and consequent injury .to the equipiiiant prevented.

With the above-recited objects and others of a similar nature in view, the invention consists in the construction, combination and arrangement of parts, set forth in. and

Speccaton of Letters Patent.

Patented J une 4, 1912. RESSUED fallingl within the scope of the appended claims.

In the accom pa nylug drawing:-Fi;ure l is ar perspective View of my improved safety fuse, he terminals of the caps beingr olnitted. Fig. .2 is a vertical longitudinal sectional view of the same. Fig. 3 is a top plan view of one ofthe fusible ring heads. Fig. 4E is a View in side el( ation of the same. Fig. 5 is a detail sectional view taken longitudinally through a portion ot' the cylinder or shell. Fig. G is a detail view in elevation of the end of one form of fuse casing and showinibI a terminal carried by the cap. Fig. 7 is a detail view, partly in section, of a moditicd manner of attaching the ap to the cylinder or shell.

Referring` now to the accompanying drawing in detail, the numeral 1 designatesl the cylinder or shell of the device, which, in the present instance is formed of two assembled semi-cylindricalsections, which are composed of a suitable umi-conducting material. The ends of this shell. as shown in Figs. 2 and are exterior-ly threaded as at Q for the reception of the interior-ly threaded conducting' caps 3 which are designed to he connected to the usual terminals in any suitable manner. rlhe end portions Je of the shell are liieveled inwardly as at 5 for the purpose hereinafter described.

The fusible conductingr clement of my iuvention, in the present instance comprises a strip (5 of fuse wire orribbon having formed integral therewith at, each end a` spider 'i' made up ot the radiating arms 8, and the short cross arms t) at the ends thereof, these cross arms connecting the fusible see'n'ieuts l0, so that when the latter are assembeld as is shown in Fig'. 3, they form av complete conducting head or ring. As will be seen by reference to Figs. 2 and 4;, each of the ring' segments is formed of a curved crown portion 11, and a downwardly and inwardly extending or beveled lower portion 12, which is adapted to correspond wit-hand rest upon the downwardly and inwardly beveled end wall of the shell. As will be seen, I employ rings, one for each end of the shell or cylinder, and I further for the fuse wires 6, the

head spider and the segna-mts of the head or i ring as an integral struct-ure. These fusible parts may be made of any suitable conducting material, possessing the proper degree of fusiblity, such as lead alloy or the like.

In Fig. 6, I have shown the cap at the end of the shell as provided with a flat blade contact terminal 13.

In Fig. 7, instead of screwing` or threading the caps onto the ends of the shell, I form an angular or bayonet slot 14 at each end of the shell, while the cap is provided with the locking pin 15, as is shown in Fig. 7.

` From the above description, taken in connection with the accompanying drawing, the construction and manner of employing my invention will be readily apparent. The fuse is installed in the usual manner, and under the influence of an exceedingly heavy overload, or short circuit the current, {iowing through the fusible conducting element will rupture and melt the same, at the cross arms 9 of the spider 7, as the cross sectional area of all the members of the spider at this point is not quite equal to the cross sectional area of the Wire or ribbon 6, and consequently the combined current carrying capacity of all of the arms of the spider is less than the current carrying capacity of the main wire or ribbon. The consequence is that the fusing Will take place at the cross arms of the spider connecting the segments of the head or ring, so that the latter will be separated and such segments will fall away or apart from each other thereby completely opening the circuit. At the same time the fusing of the remainder of the spider and the ends of the wire 6 will occur. By beveling the end of the cylinder in the manner shown` I prevent a person inserting a Wire Within the shell and completing the circuit by bringing the ends of the Wire over the ends of the shell and fastening` the same in Contact with the caps, for should this be atten'ipted the ends of the wire would strike the screw threads and prevent the cap being secured in position.

lt n'ill be noted that I have provided an exceedingly simple yet positive and effec- -tive form of safety fuse which comprises in the presentl instance substantially but three parts, the fusible elements, the caps and the shell` so that the device may be manufactured and marketed at a relatively low cost. Furthermore, when the fuse has been ruptured, it is not. necessary to entirely discard the cylinder or casing. as the latter may again be used by the simple addition of a new fusible element. which, may be readily placed in position owing to the sectional construction of the shell or casing.

Vhilc I have herein shown and described one particular embodiment of my invention, by way of illustration, I Wish it to be understood that I do not confine myself to all the precise details of construct-ion herein set forth,tas modification and varia-tion may be made Without departing from the spirit of the invention or .exceeding the scope of .ing capacity of said connections being-less than the current carrying capacity of the main fusible portion.

2. A safety fuse comprising-a casing, and

a fusible element contained therein, the l latter comprising fusible head members each formed of connected sections, and a fusible member connecting the head mem.- bers.

3. A safety fuse comprising a casing, and

a fusible element therein, said element comprising a plurality of head members each head member being formed of separated sections, a fusible spider connecting the sections of each head, and a fusible strip connecting the spiders.

' Lt. A safety fuse comprising a casing, a fusible ring located adjacent to each end of the casing, and a fusible connection extending between the rings, said ring being adapt.; ed to be ruptured upon the operation o the fuse, substantially as described.

5. A safety fuse comprising a casing, a fusible ring formed of ar series of segments, a fusible spider connecting the segments, and a fusible strip connected to the spider.

G. A safety fuse comprising a. casing, having inwardlyY beveled ends, a fusible ring at each end of the casing and having a beveled surface corresponding to the adjacent beveled end of the casing, a fusible connect-ion extending between the rings, and conducting caps at the ends of the casing.

7. A safety fuse comprising a casing formed of sections of insulatingmaterial, a fusible member adjacent to each end of the casing, a fusible strip. fusible connections between the strips and each member, said.

connections being adapted to be ruptured byv the current in the operation of the fuse, and caps of conducting material at the ends of the casing.

8. A safety fuse comprising a casing formed of sections of insulating material, a plurality of fusible rings located spaced aparti within the casing, each ring being formed of segmental members, a fusible spider frame connecting the segmenta members, a fusible strip connecting the spiders, and conducting caps for lthe ends of the casing.

9. A safety fuse comprising acasing, a fusible strip therein, a fusible spider formed 

